Hydroplanes



Feb. 20, 1968 P. T. M. NOTT 3,369,513

HYDROPLANES Filed Jan. 4, 1966 'Z'Sheet'S-Sheet 1 INVENTOR QETER \\bh\\S M NCE Nan-r m M3 M31 ATTORNEY Feb. 20, 1968 P. T. M. NOTT 3,369,513 HYDROPLANES Filed Jan. 4, 1966 I I 2 Sheets-Shet 2 3b FIG. 4.

INVENTOR rrm T mu N\ENCE No'rr ATTORNEY 3,369,513 HYDROPLANES Peter Thomas Mence Nott, Bath, England, assignor to Anglican Developments Ltd., Leigh-on-Sea, Essex, England, a British company Filed Jan. 4, 1966, Ser. No. 518,701 6 Claims. (Cl. 114-665) ABSTRACT OF THE DISCLOSURE A hydrofoil watercraft in which a righting moment is developed during heeling of the craft and an almost horizontal steering force minimizes variations in lift during turning of the craft. The watercraft has a forward hydrofoil and an aft hydrofoil, the forward foil being pivotal to effect steering and includes two foils defining an inverted V. These foils provide the entire lift for the forward end of the craft. The craft is steered by means of handlebars secured to the forward hydrofoil unit.

This invention relates to a water craft of the hydroplane type and has for its object to provide such a craft, mainly for sporting or recreational purposes, which is adapted to be ridden or driven and controlled in a similar manner to a motorcycle on land.

With this object in view the water craft according to the invention comprises a hull, a power unit for propelling the craft, at least two hydrofoil units mounted in tandem below the hull, at least one of said hydrofoil units being pivotally mounted and serving as a combined lifting and steering means for the craft.

More specifically the invention consists of a water craft comprising a hull, a power unit for propelling the craft, a hydrofoil unit fixedly mounted below the hull towards the after end of the craft and a hydrofoil unit pivotally mounted below the hull towards the forward end of the craft, said pivotally mounted forward hydrofoil unit being so constructed and arranged as to impart lift to the craft and to effect steering of the craft.

In order that the invention may be more clearly understood one particular embodiment thereof will now be described, by way of example, with reference to the accompanying drawings in which: I

FIGURE 1 is a perspective view of a hydroplane-type water craft according to the invention, and

FIGURES 2, 3 and 4 are diagrams illustrating the manner in which the lifting and steering hydrofoil reacts and the forces generated thereby under varying conditions.

Referring now to FIGURE 1 of these drawings the craft comprises a hull I, a power unit 2 for propelling the craft, a seat 9 for the rider or driver, a forward pivoted hydrofoil unit and a fixed after hydrofoil unit arranged in tandem below the hull and indicated generally at 3 and 4 respectively.

The hydrofoil unit 4 fixed below the hull at or near the after end of the craft comprises a hydrofoil 4a disposed in a substantially horizontal plane and a stabilising fin portion 4b disposed in a substantially vertical plane. The hydrofoil 4a is rigidly attached to or integral with the stabilising fin 4b and the hydrofoil unit is mounted on the lower end of a fixed supporting column 8 which is rigidly attached to the hull 1 and may be vertically disposed as shown or slightly inclined forwardly and downwardly.

The forward hydrofoil unit 3 comprises a two-bladed hydrofoil of inverted substantially V-shape cross-section, the blades 3a and 3b being arranged at an angle of 90 relative to each other. The hydrofoil unit 3 is rigidly mounted, by means of a bracket 4, on the lower end of a shaft which is rotatably mounted in a sleeve-like bear- States Patent 0 ing 6 passing through the hull 1 and which is provided at its upper end with handle bars 7. The shaft 5 is slightly inclined forwardly and downwardly relative to the longitudinal horizontal axis of the hull and controls (not shown) for the power unit 2 may be mounted on the handle bars 7 and connected with the power unit in known manner.

The hydrofoil unit 3, by virtue of its construction, arrangement and mounting, as above described, serves both as a rudder for steering the craft and a means for imparting lift thereto.

The blades 3:: and 3b may be made of a slightly flexible material, such as fibre glass, and the mounting of said blades may be so arranged as to cause a reduction of angle of incidence when an increase in load deflects the blades, the. effect of which is to reduce shock when contacting waves and to damp out pitching movements of the craft.

Referring now to FIGURES 2, 3 and 4, the reaction of the V-shape hydrofoil is as follows:

When the craft is in motion and on an even keel, i.e. in the vertical or upright position, the front hydrofoil 3 is only partly submerged, as indicated in FIGURE 2, and the two blades 3a and 3b are subjected to equal forces a, b which provides a vertical resultant force c to support the weight of the craft. If the craft heels over, for example as shown'in FIGURE 3, the blade 3a becomes more deeply immersed and generates a greater force b while the blade 3b is immersed to a lesser extent and the force a on said blade is reduced, whereby the resultant force 0 provides a righting moment automatically without any adjustment of the steering being necessary. FIGURE 4 illustrates the additional forces created by an alteration in the position of the hydrofoil to steer the craft, that is when the craft is turning. These forces are superimposed on the forces imparting lift to the craft and, due to the different lengths of blade immersed, produce an approximately horizontal force 0 whereby the course or direction of the craft is altered without causing the craft to rise or fall although heeled over.

It will be understood that various modifications can be made to the craft without departing from the scope of the invention as defined in the appended claims. For example in the embodiment shown the blades 3a and 3b of the hydrofoil 3 are arranged at an angle of approximately relative to each other, this angle may however be varied. Furthermore the blades may not necessarily be flat plane blades but might be slightly curved.

Iclaim:

1. A hydrofoil craft of the hydroplane type comprising in combination:

a hull;

a power unit for propelling the craft;

an aft hydrofoil unit fixedly mounted below the hull and located adjacent to the aft end of the craft;

a forward hydrofoil unit for steering the craft and for providing the lift for the forward end thereof, said hydrofoil unit being mounted in its entirety below the bottom of the hull adjacent to the forward end thereof, and composed of two foils at an angle of about 90 with each other to form an inverted V-shape the apex line of which faces the hull bottom; and

steering means rotatably extending through the hull bottom and fixedly connected with the forward hydrofoil unit at the apex line thereof for rotating said unit jointly with the steering means in reference to the bull to effect steering of the craft independently of said power unit.

2. A watercraft as claimed in claim 1 and comprising mOunting means for said forward hydrofoil unit, said mounting means including a shaft, a sleeve-like bearing passing through the hull of the craft, and journaling said shaft, said hydrofoil unit being secured to the lower end of the shaft, and actuating means mounted at the upper end of the shaft for rotating the same to effect said rotation of the hydrofoil unit about the apex line thereof.

3. A watercraft of the hydroplane type comprising in combination: a hull; a power unit for propelling the craft; an aft hydrofoil unit disposed below the hull and located toward the aft end of the craft; a forwardly inclined supporting column rigidly attached to the hull of the craft, said aft hydrofoil unit being fixedly mounted on the lower end of said column and including a hydrofoil disposed in a substantially horizontal plane and a stabilising fin disposed in a substantially vertical plane; a two-bladed forward hydrofoil unit of inverted substantially V shape disposed completely below the hull adjacent the forward end of the craft, the apex line of the hydrofoil unit facing the hull bottom; a shaft downwardly and forwardly inclined relative to the longitudinal horizontal axis of the hull; and a sleeve-like bearing passing through the hull of the craft, said forward hydrofoil unit being mounted on the lower end of said shaft for rotation in unison therewith to effect steering of the craft; and

control means secured to the upper end of said shaft for rotating the same.

4. A watercraft of the hydroplane type according to claim 1, wherein said forward hydrofoil unit comprises a pair of foils and mounted so as to cause a reduction in the angle of incidence when an increase in load deflects said foils.

5. A watercraft of the hydroplane type according to claim 1, wherein said forward hydrofoil unit is provided with foils of a slightly flexible material, and is so mounted as to cause a reduction in the angle of incidence when an increase in load deflects said flexible foils.

6. A watercraft of the hydroplane type comprising in combination: a hull; a power unit for propelling the craft; an aft hydrofoil unit disposed below the hull toward the aft end of the craft; a slightly forwardly inclined support column rigidly attached to the hull of the craft, said aft hydrofoil unit being fixedly secured to the lower end of said column; a forward hydrofoil unit of inverted substantially V-shape disposed below the hull toward the forward end of the craft, the foils of said forward hydrofoil unit being of slightly flexible material and so mounted as to cause a reduction in angle of incidence when an increase in load deflects said foils; a shaft; 21 sleeve-like bearing passing through the hull of the craft and journaling said shaft, said forward hydrofoil unitbeing mounted on the lower end of said shaft for rotation in unison therewith to effect steering of the craft and means for manually rotating said shaft mounted at theupper end thereof.

References. Cited UNITED STATES PATENTS 1,515,649 11/1924 Baldwin 11466.5 1,835,618 12/1931 Waller 114-66.5 2,955,559 10/1960 Palmer et al. l14--66.5 3,081,728 3/1963 Wilterdiuk et a1. 114-665 3,124,096 3/1964 Graig 11466.5

ANDREW H. FARRELL, Primary Examiner. 

